In general, the discriminant is .

In this particual case .

Plug in these three values and simplify:

For the equation 

to have two imaginary solutions, its discriminant  must be negative. Set  and solve for  in the inequality

Therefore, if  is a positive integer, it must be in the set .

For the equation 

to have two real solutions, its discriminant  must be positive. Set  and solve for  in the inequality

Therefore, if  is a positive integer, it must be in the set 

The "discriminant" is the name given to the expression that appears under the square root (radical) sign in the quadratic formula,  where , , and  are the numbers in the general form of a quadratic trinomial: . If the discriminant is positive, the equation has real roots, and if it is negative, we have imaginary roots. In this case, , , and , so the discriminant is , and because it is negative, this equation's roots are not real.

Remember the quadratic formula:

.

The discriminant in the quadratic formula is the term that appears under the square root symbol. It tells us about the nature of the roots.

So, to find the discriminant, all we need to do is compute  for our equation, where .

We get .

The number of roots can be found by looking at the discriminant. The discriminant is determined by . For this function, ,, and . Therfore, . When the discriminant is positive, there are two real solutions to the function.

The discriminant is found using the equation . So for the function , ,, and . Therefore the equation becomes .

Given that quadratics can be written as . The discriminant can be found by looking at  or the value under the radical of the quadratic formula. Using substiution and order of operations we can find this value of the discriminant of this quadratic equation.

The discrimiant will determine how many solutions a quadratic has. If the discriminant is positive, then there are two real solutions. If it is negative then there are two immaginary solutions. If it is equal to zero then there is one repeated solution.

Given that quadratics can be written as . The discriminant can be found by looking at  or the value under the radical of the quadratic formula. Using substiution and order of operations we can find this value of the discriminant of this quadratic equation.

The discriminant is positive; therefore, there are two real solutions to this quadratic.

This is using the discriminant to find roots. The discriminant as you recall is

If you get a negative number you have no real roots, if you get zero you have one, and if you get a positive number you have two real roots.

So plug in your numbers:

Because you get a negative number you have zero real roots.